What if George only changed the special effects, but still had Han shoot first, Vader say "bring my shuttle", Shaw at the end of Jedi, Lapti Nek and Yub Yub in Jedi, no Jabba scene in SW, no new voice for Boba Fett, the original Emperor in Empire, no extra Biggs scene before the Battle of Yavin, etc etc. These seem like the biggest complaints from fans including myself.
I really don't think fans would have complained as much if the only changes had been the updated special effects in spots. As long as the cgi didn't change any of the storyline or pacing of the films, I don't think fans would be so annoyed. I also think it was ridiculous for George to change more than the special effects, because all of that goes against his original vision garbage. If his original vision was to have Greedo shoot first or to have a different song in Jabba's palace and in the celebration, those things would never have made the films to begin with!